Methane on Mars

Abstract

Volume 3 • Issue 1 • 1000125 Astrobiol Outreach ISSN: 2332-2519 JAO, an open access journal Finally, the Eureka Moment! In 2004, the first reports of methane (CH 4) in Mars' atmosphere, by both Mars Express and ground-based observations, stirred up excitement in the scientific community [1,2]. These detections (at 10 ppbv level) immediately raised questions regarding the origin of methane. On Mars, oxidants and UV radiation destroy atmospheric methane in approximately 300 yrs [3]. Therefore, the presence of atmospheric methane requires ongoing or recent methane emission. On Earth, methane is almost entirely of (live and fossil) biological origin, while abiotic sources, believed to be predominantly volcanic and/or hydrothermal, account for the rest (a few percent) of the total CH 4 flux into the atmosphere [4]. The conventional understanding of Mars is in stark contrast: decades of exploration have not found life or active volcanism, although localized outgassing sources cannot be ruled out, and we know that past Martian volcanism until perhaps only a few million years ago had existed [5]. Consequently, a methane detection impacts Mars science and astrobiology in very fundamental ways. It turns the theoretical musing of possible life on Mars into a necessary investigation component for interpreting observational data. It elevates the possibility of hydrothermal activity on Mars, which can be habitable environments providing liquid water and redox energy to sustain life. Moreover, it compels new research directions to explore novel processes that can produce methane on Mars.